The next quantum step forward in the treatment of Parkinson's disease will be the development of therapies which slow the progression of the disease. Testing of new agents will require recruitment of recently diagnosed Parkinson's disease subjects and retention of them in therapeutic trials lasting five to ten years. The extensive experience of the Oregon Health & Science University Parkinson Center of Oregon in conducting clinical trials, specifically long trials in recently diagnosed subjects, supports our inclusion in a cooperative multicenter trial of neruoprotective agents for Parkinson's disease. We also propose a number of means by which we may increase enrollment of de novo subjects, including subjects from minority groups, and retain them in the study. In addition, long-term trials of neuroprotective agents in early Parkinson's disease offer a unique opportunity to study the natural history of family care giving, assess caregiver strain as an outcome variable for new therapeutics and identify potential interventions to reduce care giving strain. These studies will extend and expand the preliminary studies of family care giving in Parkinson's disease we have done in the Parkinson Study Group DATATOP cohort.